Idiopathic omental infarction, diagnosed and managed laparoscopically: a case report

Are all primary omental infarcts truly idiopathic? Five case reports

BACKGROUND

Idiopathic omental infarction (IOI) is challenging to diagnose due to its low incidence and vague symptoms. Its differential diagnosis also poses difficulties because it can mimic many intra-abdominal organ pathologies. Although hypercoagulability and thrombosis are among the causes of omental infarction, venous thromboembolism scanning is rarely performed as an etiological investigation.

CASE SUMMARY

The medical records of the 5 cases, who had the diagnosis of IOI by computed tomography, were examined. The majority of the patients were male (n = 4, 80%) and the mean age was 31 years (range: 21-38). The patients had no previous abdominal surgery or a history of any chronic disease. The main complaint of all patients was persistent abdominal pain. Omental infarction was detected in all patients with contrast-enhanced computed tomography. Conservative treatment was initially preferred in all patients, but it failed in 1 patient (20%). After discharge, all patients were referred to the hematology department for thrombophilia screening. Only 1 patient applied for thrombophilia screening and was homozygous for methylenetetrahydrofolate reductase (A1298C mutation) and heterozygous for a factor V Leiden mutation.

CONCLUSION

IOI should be considered in the differential diagnosis in patients presenting with progressive and/or persistent right side abdominal pain. Investigating risk factors such as hypercoagulability in patients with IOI is also important in preventing future conditions related to venous thromboembolism.

Omental infarction and anterior wall adhesion presenting as surgical abdomen in a pediatric patient

Omental infarction is a rare cause of acute abdomen that can present in both the pediatric and adult populations causing adhesions or abscesses. Presentation may mimic appendicitis; however, ultrasonography may not be sufficient. We discuss the importance of CT imaging for the pre‐surgical diagnosis to avoid serious port‐site injuries.

"Tethered Fat Sign": The Sonographic Sign of Omental Infarction

Our purpose is to describe the ultrasound sign for a correct non-invasive diagnosis of omental infarction in children. From January 2014 to December 2018, a total of 234 children (109 boys and 125 girls, age range 3-15 y) with acute right-sided abdominal pain, admitted to our hospital with a presumptive diagnosis of acute appendicitis, were prospectively evaluated. In all patients, abdominal ultrasound was performed, and the omental fat was always evaluated. In 228 patients, the omental fat resulted to be normal or hyperechogenic, never tethered, and they results affected by other causes of abdominal pain different from omental infarction (such as appendicitis, pancreatitis, urolithiasis and others). In the remaining 6 children, we found a hyperechoic mass between the anterior abdominal wall and the ascending or transverse colon in the right abdomen quadrant, suggesting the diagnosis of omental infarction. This subhepatic mass was always tethered to the abdominal wall, motionless during respiratory excursions. We named this finding the "tethered fat sign." The diagnosis was confirmed with laparoscopy in 4 children. The other 2 children were treated with conservative therapy. In these 2 patients, a sonographic follow-up was performed, showing a progressive reduction in size of the right-sided hyperechoic mass. In conclusion, our study suggests that the presence of the "tethered fat sign" may be an accurate sonographic sign for non-invasive diagnosis of omental infarction in children.

Multislice computed tomography evaluation of primary abdominal fat necrosis: a rare cause of acute abdominal pain

Purpose

Abdominal fat necrosis is a rare cause of abdominal acute pain, classified into primary or secondary according to the cause. Primary fat necrosis includes epiploic appendagitis or idiopathic infarction of the greater omentum. This retrospective study focuses on multislice computed tomography (MSCT) findings and diagnosis of primary abdominal fat necrosis as a cause of acute abdomen.

Material and methods

This was a retrospective study with 20 patients included, presented to emergency room with acute abdominal pain diagnosed as primary fat necrosis. Retrospective evaluation was made of the patients’ clinical data, presentation, CT studies done at the acute stage, and their primary and final diagnosis.

Results

Twenty patients (eight male and 12 female, mean age 45 years, age range 20-70 years) diagnosed with abdominal fat necrosis (primary omental infarct) on CT imaging between October 2014 and June 2018 were evaluated. Clinically, five patients were suspected to be cholecystitis¸ eight patients as appendicitis, and four patients as diverticulitis. In addition, three patients had renal colic and were suspected to have ureteric stones; they showed suspected areas of abnormal fat density in non-contrast CT of the urinary tract. Idiopathic omental infarctions were detected in 13 patients on CT; all were on the right side. Laparoscopic excision was done for all. The other seven patients had epiploic appendagitis, seen on the left side, treated with conservative management.

Conclusions

Primary fat necrosis, although rare, can be presented as acute abdomen. MSCT is the main diagnostic tool for diagnosis of omental infraction and differentiation between other causes of acute abdomen.

Omental infarction and its mimics: imaging features of acute abdominal conditions presenting with fat stranding greater than the degree of bowel wall thickening

The segmental omental infarction is a rare self-limited disorder presenting with aspecific clinical symptoms that may mimic several acute abdominal conditions. Therefore, a correct noninvasive diagnosis is important because treatment approaches range from monitoring to surgery. As omental infarction results in an important fat stranding that is much greater than the degree of bowel wall thickening, it suggests a narrower differential diagnosis: appendicitis, diverticulitis, epiploic appendagitis, and mesenteric panniculitis. In this pictorial essay, we point out the importance of imaging in identifying this typical sign allowing alternate diagnoses such as segmental omental infarction that can be conservatively managed.